Don't quote {posargs} in tox.ini
Don't quote {posargs} in tox.ini

Quotes around {posargs} cause the entire string to be combined into one
arg that gets passed to stestr. This prevents passing multiple args
(e.g. '--concurrency=16 some-regex')

Change-Id: I55af786294e812d8942ac934f947f04cd3d459d9
Closes-Bug:  #1801451

openstack/os-apply-config